Needle-guide device, particularly for ultrasound probes

ABSTRACT

A needle-guide device, particularly for ultrasound probes, or the like, comprising a base body having means for connection to the probe and at least one elongated guide hole for receiving a needle-like surgical tool, characterized in that said needle-guide device, is made of at least two removably connectable parts, which are shaped in such a manner that each of them forms complementary parts of the peripheral delimiting wall of the elongated guide hole for the surgical tool which peripheral wall parts complete each other when said two parts, of the needle-guide device are connected, thereby forming an elongated guide hole for guiding the needle with a 360° covering delimiting wall.

REFERENCE TO RELATED APPLICATION

The present patent application claims foreign priority benefits under 35U.S.C. §119 to Italian patent application No. SV2001A000008, filed Mar.5, 2001, now pending.

BACKGROUND OF THE INVENTION

The present invention relates to a needle-guide device, particularly forultrasound probes, or the like, comprising a base body having means forconnection to the probe and at least one elongated guide tube for anelongated, rodlike diagnostic or surgical tool, named needle.

Such devices are currently used to accurately guide diagnostic ortherapeutic tools, such as needles for biopsy, thermoablation,alcoholization or localized injection of substances, especially ofchemotherapeutic agents.

However, the word needle is used in the present description and inclaims, to define any diagnostic or therapeutic tool for localizedoperation, which has a rodlike conformation, for at least a portion ofits extension, for instance for a portion of a support stem of the tool.

Localized applications, such as biopsies, thermoablation or localizedinjection of therapeutic substances are currently performed incombination with imaging means, and particularly in combination withultrasound probes. Ultrasonic imaging allows to see the needle, or atleast one of the needles and the target region to safely orient and movethe needle to the target point.

The needle/s are moved to their position by appropriately orienting theprobe manually or mechanically and/or by sliding them inside a guideseat. Hence, the probe shall have a needle-guide for safely and stablyaccommodating the needle, thereby avoiding any mutual staggering andwrong positioning or insertion of the needle/s.

To this end, needle-guide devices such as the one described hereinbeforeare known, which comprise an elongated cannula-shaped hole, or the like,wherein the needle is inserted.

These devices have the drawback of not allowing a sufficiently safesterilization. In fact, hardly removable microbial residues mayinfiltrate in the elongated holes or cannulae. For this reason,single-use needle-guides of the above type are currently known,particularly made of plastic. However, this involves some drawbacks.Besides obvious cost drawbacks (considering that stable attachment ofultrasound probes often requires rather complex adaptations of theneedle-guides, thereby involving rather high fabrication costs),material waste is caused, with a consequently higher environmental loadand the materials in use do not often have a good stability, forinstance to thermal action, which is a critical condition, inapplications like thermoablation.

Therefore, the invention has the object of providing a needle-guide suchas the one described hereinbefore which, by relatively inexpensiveconstruction arrangements, allows to obviate the drawbacks of prior artneedle-guides. Also, the invention has the object of improvingneedle-guides to achieve a better functionality with reference to thediagnostic and/or therapeutic techniques which use those tools.

The invention achieves the above purposes by providing a needle-guide asdescribed hereinbefore, which is made of at least two removablyconnectable parts, which two parts are shaped in such a manner that eachof them forms complementary parts of the peripheral delimiting wall ofthe elongated hole and/or cannula for the needle (3), which completeeach other when said two parts of the needle-guide are connected,thereby forming an elongated hole for guiding the needle or a cannulawith a 360° covering delimiting wall.

Particularly, the two needle-guide parts have mutual abutment surfaceswhich are tangent or secant to the elongated needle-guiding hole,whereas this hole is obtained by a combination of grooves which areformed either integrally on one of the mutual abutment surfaces of oneof the two needle-guide parts or partly on one and partly on the otherof the two abutment surfaces of both needle-guide parts.

The separation plane between the two needle-guide parts is parallel tothe axis of the elongated hole and secant or substantially tangent tothe hole.

The elongated needle-guiding hole may be provided with a sectioncorresponding to the outer section of the needle, with the wall of theelongated hole adhering to the whole needle surface.

Possibly and advantageously, the elongated needle-guiding holes may alsohave polygonal, particularly square or rectangular sections, said squareor rectangular sections having such a size as to be able to inscribetherein the cylindrical or elliptical or oval section of the needle.This provides the advantage of a wider range of position choices for theseparation plane between the two needle-guide parts in the elongatedhole area, there being no undercut situation if the separation planeintersects the hole with an orientation parallel to at least two sidesthereof. Moreover, since the needle has to be held accurately as regardsorientation but must be able to slide inside the hole in the directionof its axis, the use of rectangular or square holes limits the contactsurfaces between the needle and the guide hole wall to individualtangent lines or bands, thereby obtaining a lower friction between theneedle and the hole wall (friction force being also proportional to thecontact surface) and an effective and safe hold of the needle in theoriented position.

According to an advantageous embodiment, the needle guide is composed ofat least two removable parts, at least one base part and at least onesecond part, which two parts are separated from each other by aseparation surface whose cross section is a broken rectangular curve,and forms a succession of alternate and parallel complementaryengageable ribs, there being provided, in the opposite mutual abutmentsurfaces of the ribs of one or both of the two needle-guide parts,grooves having such a size and shape as to form together an elongatedneedle-guiding hole or cannula.

The broken rectangular line-shaped separation surface between said twoneedle-guide parts may have variable widths and generate guiding holeswith different relative positions.

Obviously, the needle-guide may be divided in such a manner as toconsist of more than two parts, for instance three parts, shaped in sucha manner as to form complementary parts of the peripheral delimitingwall of the needle-guiding elongated hole or cannula.

Advantageously, in a preferred embodiment, the needle-guide is composedof a base for connection to the ultrasound probe, which has at least onelongitudinal groove, for engaging longitudinally continuous ordiscontinuous extensions of the side walls of a longitudinal grooveprovided in the other needle-guide part. Here, the bottom of thelongitudinal groove in the base forms the complementary part forcompleting the elongated hole or cannula, whose other peripheral wallsconsist of the bottom of the longitudinal groove of the otherneedle-guide part, of the side walls of said groove and of theextensions of said side walls of the groove in the second part of theneedle-guide.

By this arrangement, at least but not only in the disassembledcondition, the elongated hole is longitudinally completely open, wherebyit may be cleaned and sterilized with the highest safety but, unlike thecase of the separation plane secant to the elongated hole or cannula andparallel to the longitudinal axis thereof, a perfect mutual centeringeffect between the two needle-guide parts is ensured, as well as astable hold of said proper position with reference to transversestaggering.

Obviously, alternatively to the above, instead of two extensions of theside walls of the longitudinal grooves of the second needle-guide part,the second needle-guide part may be arranged to have a single extensionof one of the two side walls of the longitudinal groove, whereas theother extension may be provided on the base part, as an extension of theopposite side wall of the longitudinal groove in the base part of theneedle-guide. Here, each of the two parts of the needle-guide forms twoof the opposite walls of the elongated hole or cannula.

The arrangement of the extensions of the side walls of the grooves inthe two parts of the needle-guide may be also alternate andcomplementary over the length of the two extensions in the longitudinaldirection of the grooves, either on one side and along the two oppositesides.

The second part of the needle-guide may be stably and removably securedto the needle-guide base in any manner, and particularly by means ofscrew-threaded devices, such as fastening bolts, or the like. In aparticularly advantageous embodiment, one of the parts of theneedle-guide, particularly the base part, has a wall parallel to theconnecting direction, i.e. perpendicular to the separation plane, whichhas a recess for accommodating a fastening bolt which is screwed into athreaded hole formed in the other part, in an adjacent wall, adheringagainst said wall of the first part of the needle-guide. Alternativelyto using bolts, said second part of the needle-guide may have a threadedpin of such a length as to project beyond the wall of the first part,through the recess provided in said wall and onto which threaded pin anut screw is tightened.

Alternatively, the two mutually adhering walls of said two parts of theneedle-guide may have, the inner one, a threaded hole and the other onea through hole, a threaded bolt with a tightening head being provided tofasten said two walls together.

According to an additional characteristic, the needle-guide may have aslender or tapering head, particularly having rounded edges, especiallybeing wedge-shaped.

As a whole, the needle-guide may have a shape tapering toward the frontend, especially a wedge shape. This is particularly advantageous incombinations of the above needle-guide with endocavitary probes, such asfor uterine biopsy applications or the like.

In order to limit the presence of discontinuities, which might causedamages or pain to the patient, the front head, also perforated, isarranged to be a single piece, and preferably made of one piece with thebase part of the needle-guide.

In this case, the through hole in said head part is widened on at leastone side or for a portion of its inner delimiting surface, the secondpart of the needle-guide being provided, on its end side, with a wallextension which may be axially fitted in the through hole of the fronthead, coinciding with said wider portion and complementary thereto so asto complete, even in the front head of the needle-guide, the delimitingwall of the elongated through hole.

Advantageously, the second part of the needle-guide has said extensionson two opposite sides and in the form of front extension wings of thetwo side walls of the groove provided in said second part of theneedle-guide, whereas the front head of the needle-guide hascomplementary widened portions in the corresponding walls.

In a further improvement, the bottom wall of the groove of the secondneedle-guide part also has an extension wing, the front head of theneedle-guide being arranged to be accordingly widened even in the areaof said extension wing of the bottom side of the groove of the secondneedle-guide part.

The extension wings of the side and/or bottom walls of the groove in thesecond part of the needle-guide are thinner than the wall of the secondpart of the needle-guide and than the head of the needle-guide, wherebyan abutment step is formed between the front end of the second part ofthe needle-guide and the facing rear end side of the front head.

In accordance with an additional advantageous characteristic, the fronthead of the needle-guide, which is integral with the base part of theneedle-guide, has a through aperture which communicates with theelongated hole provided therein at at least one of the sides of saidhead, preferably at one of the two transverse sides, not coinciding withthe extension wings of the second part of the needle-guide andparticularly at the side of the base part of the needle-guide which isopposite the second part of the needle-guide and meant to adhere againstor turned toward the probe, whereas in the front head, the needle isonly substantially guided on three sides and through less than 360° atleast in coincidence with the through aperture.

Advantageously, the front head of the needle-guide is relatively shortas compared with the length of the rest of the needle-guide, in whichthe elongated hole or cannula have a continuous delimiting surface.

According to a further improvement, the front head of the needle-guidehas a steeper tapered front end than the remaining portion of said headon the side connected to the second part of the needle-guide, whereas insaid end portion and in the wall opposite the one with the aperture, theneedle projection opening is provided, which takes an elongated shape,and in said end, the elongated hole delimiting walls are continuous andmade of one piece, as well as directly accessible from the entryaperture.

Particularly, said front end of the front head of the needle-guide stillhas a needle guiding surface on the aperture side opposite to the onewherein the second part of the needle-guide fits, which surface extendsfrom the front end of said aperture to the front apex of the front head.

As stated above, the needle-guide is designed to be mounted on anultrasound probe, wherefore the invention also relates to a combinationof a needle-guide and an ultrasound probe, wherein the base of theneedle-guide is removably attachable to the probe body in a stable andpredetermined position, said base having one or more shape matingextensions which adhere to a portion of the outer surface of theultrasound probe body and/or mutual interlock engagement means, as wellas clamping means.

In one embodiment, the needle-guide as described herein, having atapered front head is designed to be connected to an endocavitary probe,which typically has a substantially cylindrical or other similar shape,also being elongated and having a rounded head, the base of theneedle-guide having a surface whereby it rests on the probe case only ina few partial portions of the longitudinal extension and particularly inthe end portions of the base of the needle-guide.

Further, the facing surfaces of the base of the needle-guide and of theprobe case have complementary centering projections and recessesarranged over their length.

According to an improvement, the probe case may have recesses foraccommodating supporting feet or extensions of the base of theneedle-guide, provided at least at the ends thereof.

Particularly, the front head of the needle-guide has a front engagementextension on the side turned toward the probe case, which is designed toengage in a recess of the probe case, in such a manner that the taperedend of said front head can be connected thereto without forming outersteps or discontinuities.

In this case, since the centering pins and the means for engaging thefront head of the needle-guide to the probe are effectiveposition-holding means for the base of the needle-guide, theneedle-guide is removably secured to the probe by means of a clampingcollar provided at the rear end portion of the needle-guide.

An additional embodiment of the needle-guide combined with an externalultrasound probe having a bulged shape and a wider head as compared withthe handgrip, has a base with two front extensions for resting onpreferably symmetrically coincident front widened portions of the bulgedshape, and an extension with a fastening screw which overlaps the rearside of the widened head against which the fastening screw is tightened.The fastening action so obtained is substantially concentrated in threepoints and is highly stable.

According to a further improvement, the needle-guide may have two, threeor more elongated holes or two, three or more elongated guiding cannulaewhich are arranged in such a manner as to bring at least one of theneedles in an ultrasound probe imaging position, whereas the otherneedle/s have predetermined and fixed positions relative to the former.

Hence a proper guiding action of the needle set is obtained, and thetarget area may be widened, for instance for a thermoablationapplication or for a localized injection of substances.

Advantageously, the invention proposes that this needle-guide type isalso composed of two parts, a separation plane or surface being providedbetween the at least two parts, which is parallel to the axis of thecorresponding elongated hole or cannula, and is secant or at leasttangent to the corresponding hole, so that, by the separation betweensaid at least two parts, all the elongated holes or cannulae arelongitudinally open on at least one portion of a side.

Here again combinations of grooves and walls may be provided in said twoparts which, by their mutual engagement, simultaneously form thecomplementary parts of the delimiting surfaces of the two, three or moreholes in the needle-guide.

In an advantageous embodiment which includes three needle guidingelongated holes or cannulae and in which the needle-guide is dividedinto a base and a second part to be removably fastened to the base, thebase of the needle-guide has a groove which accommodates the second partof the needle-guide, and has longitudinal side walls and a bottom wall,whereas an additional narrower groove is provided in the middle of thebottom wall and in turn has an additional groove in its bottom wall,which forms two longitudinal side walls and a longitudinal bottom wallfor guiding the needle, whereas the second part of the needle-guide has,on the surface turned toward the bottom of the housing groove, alongitudinal median rib which coincides with the narrower longitudinalmedian groove in the base part and forms the missing needle guidingsurface, completing the surfaces provided in the third groove, whereas,in the surfaces of the second part of the needle-guide, on the two sidesof the longitudinal medial rib, longitudinal grooves are provided whichform, with the facing surfaces of the first groove for accommodating thebase part, at the two sides of the median groove, the delimitingsurfaces of the two additional needle guiding elongated holes.

The advantages of the present invention are self-evident from the abovedescription. The needle-guide device may be easily disassembled andallows to access the guiding elongated holes for a complete and safesterilization. This allows to manufacture reusable needle-guides, frommetal materials which do not involve drawbacks in various applications.

The needle-guide of the invention perfectly fits any application, asproven by the application embodiments to both endocavitary and externalprobes.

It shall further be noted that the individually describedcharacteristics may be provided in any combination, even regardless ofthe individual specific embodiments.

The invention relates to further improvements which will form thesubject of the appended claims.

SUMMARY OF THE INVENTION

A needle-guide device, particularly for ultrasound probes, according toone embodiment of the present invention comprises a base body havingmeans for connection to an ultrasound probe and at least one elongatedguide tube for an elongated, rodlike diagnostic tool characterized inthat the needle-guide is made of at least two removably connectableparts which are shaped in such a manner that each of them formscomplementary parts of a peripheral delimiting wall of an elongated holefor cannula for the needle which peripheral wall parts complete eachother when the two parts of the needle-guide are connected, therebyforming the elongated hole for guiding the needle (or cannula) with a360 degree covering delimiting wall.

A needle-guide device, particularly for ultrasound probes, according toanother embodiment of the present invention comprises a base bodyconstructed and arranged for connection to a probe and at least oneelongated guide tube for an elongated, rodlike diagnostic tool,characterized in that the needle-guide device has a plurality ofelongated holes or a plurality of cannulae for guiding a plurality ofneedles or rod-like tools which are arranged with their axes coincidentwith a single plane or having axes arranged on more than one plane,particularly having hole axes arranged at the vertices of idealpolygonal elements, such as triangles, quadrilaterals, or the like, orin any other different mutual arrangement.

A combination of a needle-guide device and an ultrasound probe accordingto another embodiment of the present invention comprises a hand gripportion characterized in that a base of the needle-guide is removablyattachable to a body portion of the probe in a stable and predeterminedposition, the base having one or more shape mating extensions whichadhere to a portion of the outer surface of the ultrasound probe bodyand mutual interlock engagement features and clamping means.

One object of the present invention is to provide an improvedneedle-guide device for an ultrasound probe as well as a needle guidedevice in combination with an ultrasound probe.

Related objects and advantages of the present invention will be apparentfrom the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the rear side of an endocavitaryultrasound probe, whereto a needle-guide according to a first embodimentof the invention is connected.

FIG. 2 is a sectional view of a detail of the probe as shown in FIG. 1,with a needle-guide as shown in FIG. 1 connected thereto.

FIG. 3 is a perspective view of the needle-guide only, as shown in theprevious Figures, and as seen from the front side.

FIG. 4 is a perspective view of the needle-guide as shown in FIG. 3, andas seen from the other side.

FIG. 5 is a side elevational view of the FIG. 3 needle-guide.

FIG. 6 is a bottom plan view of the FIG. 3 needle-guide.

FIG. 7 is a rear elevational view of the FIG. 3 needle-guide.

FIG. 8 is a perspective view like that of FIG. 3, in which the two partsof the needle-guide are shown separately, in exploded view form.

FIG. 9 is a perspective view of the rear side of the two parts of theneedle-guide, shown in FIG. 8.

FIG. 10 is a sectional view as seen through a median plane passingthrough the axis of the needle and/or of the elongated guiding hole.

FIG. 11 is a perspective view of an additional embodiment of theprobe/needle-guide combination according to the invention, particularlyin which the probe is an external probe with a head shaped as a sectorof a circle and wider than the handgrip.

FIG. 12 is a perspective view of an additional embodiment of theprobe/needle-guide combination according to the invention, particularlyin which the probe is an external probe with a head shaped as a sectorof a circle and wider than the handgrip.

FIG. 13 is a perspective view of an additional embodiment of theprobe/needle-guide combination according to the invention, particularlyin which the probe is an external probe with a head shaped as a sectorof a circle and wider than the handgrip.

FIG. 14 is a perspective view of an additional embodiment of theprobe/needle-guide combination according to the invention, particularlyin which the probe is an external probe with a head shaped as a sectorof a circle and wider than the handgrip.

FIG. 15 is a side elevational view of the base part of the needle-guideas shown in FIGS. 11 to 14.

FIG. 16 is a bottom plan view of the base part of the needle-guide asshown in FIGS. 11 to 14.

FIG. 17 is a top plan view of the base part of the needle-guide as shownin FIGS. 11 to 14.

FIG. 18 is a top perspective view of the base part of the needle-guideas shown in FIGS. 11 to 14.

FIG. 19 is a bottom perspective view of the base part of theneedle-guide as shown in FIGS. 11 to 14.

FIG. 20 is a front elevational view of the second part of theneedle-guide as shown in FIGS. 11 to 14.

FIG. 21 is a front perspective view of the second part of theneedle-guide as shown in FIGS. 11 to 14.

FIG. 22 is a bottom plan view of the second part of the needle-guide asshown in FIGS. 11 to 14.

FIG. 23 is a front elevational view of the second part of theneedle-guide as shown in FIGS. 11 to 14.

FIG. 24 is a side elevational view of the second part of theneedle-guide as shown in FIGS. 11 to 14.

FIG. 25 is a perspective view of the needle-guide as shown in FIGS. 11to 14.

FIG. 26 is a perspective view, in partial section, of the needle-guideas shown in FIGS. 11 to 14.

FIG. 27 is a side elevational view, in partial section, of theneedle-guide as shown in FIGS. 11 to 14.

FIG. 28 is a front perspective view of the needle-guide as shown inFIGS. 11 to 14.

FIG. 29 is a rear perspective view of the needle-guide as shown in FIGS.11 to 14.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates.

Referring to FIGS. 1 to 10, the invention is shown in the form of acombination of a needle-guide 2 and an endocavitary probe 1. The probe 1has a substantially cylindrical shape with a handgrip portion 101 and ahead 201 which contains the ultrasonic pulse emitting and receivingtransducers.

The needle-guide 2 has an elongated shape with a wedge-shaped profiletapering from back to front and is composed of two connectable andseparable and removably fastenable parts 102, 202, i.e. a base part 102and a second part 202. The two parts define an elongated through holewhich extends all along the needle-guide 2 from the rear end to thefront head 9 thereof. The elongated hole is designed to accommodate arodlike tool 3 for diagnostic or therapeutic applications, particularlya biopsy needle, a thermoablation needle, or a needle for injectingchemotherapeutic agents, or the like. The elongated hole has such asize, as related to the diameter of the needle 3 as to be able to holdthe needle 3 in the proper position and to allow it to be axiallydisplaced inside the needle-guide 2.

The needle-guide 2 is disposed with its longitudinal axis having thesame front-to-back orientation as the needle in relation to the probe,in the front-to-back direction of the probe 1. Also, the elongated holefor guiding the needle 3 has such an inclination as related to the axisof the probe 1, that the front end of the needle falls within the targetscan area of the probe 1 to be imaged during use.

Advantageously, the inclination of the hole for guiding the needle 3substantially corresponds to the inclination of the free inclined end ofthe second needle-guide part 202. This provides a visual impression ofneedle inclination and facilitates the fabrication of the secondneedle-guide part.

The base 102 of the needle-guide has a clamping collar 4 at the rear end(with reference to the head 201 of the probe 1), one half 104 thereofbeing integral with said base 102, whereas the other half 204 of thecollar 4 is hinged by hinge 304 to an end of said first half 104, andthe two opposite free ends of the halves 104, 204 may be clampedtogether by screw threaded means 404 in a manner which is typical forclamping collars.

On the lower side resting on the probe 1, the base 102 has means 402,502 for centering and positioning it on the probe, consisting of ridgesor pins which cooperate with coincident recesses or notches 401 formedon the outer body of the probe 1. Possibly, the centering means 402, 502have such a height as to keep the side of the base 102 turned toward theprobe case slightly raised therefrom.

The base 102 has a surface 602 for supporting the second part 202 of theneedle-guide, whereas the second part 202 of the needle-guide has acentral groove 702 which is open toward said support surface 602. Thesecond part 202 of the needle-guide has tapered extensions 802, 902 ofthe delimiting walls of the groove 702 at its front end. The extensions802, 902 are externally tapered and extend flush with the innerdelimiting sides of the groove 702, while forming an outer step 5 withthe end side of the second part 202 of the needle-guide.

The second part 202 of the needle-guide has, at its rear side, twolateral lower wings 6, which rest on the two appropriately recessedcorresponding opposite sides 7 of the rear side of the base 102. Thelateral lower wings 6 and the rear recesses 7 have facing end sides 106,107 which form axial abutment surfaces for the needle between the twoneedle-guide parts 102, 202.

In one of the two lateral recessing surfaces 7 of the base part 102, athreaded hole is provided into which a threaded pin 8 with a tighteninghead is screwed. The corresponding wing 6 of the second part 202 of theneedle-guide 2 has a recess 206 open on the side turned toward the frontend of the needle-guide 2 and coincident with the threaded hole, inwhich the threaded pin 8 is engaged, thereby allowing the two parts ofthe needle-guide 2 to be mutually clamped. In accordance with animprovement, the threaded hole for the threaded pin 8 is a through holeand the opposite wing 6 of the second part 202 of the needle-guide alsohas a coincident hole for engaging the end of the threaded pin 8. Thelatter is of such a length that, in the clamped position, it is engagedin the hole 306 of the wing 6 without projecting therefrom, and alsoremains partly engaged in said hole 306 in an incomplete clampingposition of the threaded pin 8.

The base part 102 of the needle-guide 2 has a front head at the frontend, which is made of one piece therewith. The head 9 has a steeperfront portion 109, in which a projection opening 209 for the needle 3 isprovided, which takes a slot-like shape due to inclination. The steeperportion 109 is followed by a portion 309 having an inclinationcorresponding to that of the second part 202 of the needle-guide when itis mounted on the base 102. This portion 309 has substantially the samelength as the extensions 802, 902 of the walls of the groove 702 in thesecond part 202 of the needle-guide. The front head 9 has a hole 409 forengaging said extensions, whose internal shape is complementary to theexternal shape of the extensions, whereas the end edge of the secondpart 202 of the needle-guide 2 forms a shoulder for abutment against therear end side of the front head 9 and is connected thereto for asubstantially flush completion thereof.

A slot-like aperture 509 is provided on the front head side 9 turnedtoward the probe 1 and lying over the open side of the extension of thegroove 702, coincident with said extension, which aperture extendstransversely all along the engagement hole 409 of the front head 9. Atthe more tapered end 109 of the front head 9, the side turned toward theprobe 1 is closed and is completely accessible from the needleprojection hole which, due to the inclination in the corresponding sidehas the shape of a slot. Further, at said end side 109, the front head 9has an extension 609 toward the probe 1 which is designed to be engagedin a complementary recess 501 formed in the case of the probe 1. Thedepth of the recess and the profile of the probe and of the frontportion 109 of the head 9 of the needle-guide are such that, in theassembled position, the steeper front side 109 of said front head isjoined to the outer surface of the case of the probe 1 substantiallywithout forming any step therewith, and being connected therewith in asubstantially harmonic manner.

In the embodiment as shown in the Figures, the separation plane betweenthe two parts 102, 202 of the needle-guide 2 is substantially tangent tothe lower side of the hole for guiding the needle 3, which is formed bythe side for supporting the second part 202 of the needle-guide 2 on thebase part 102 of the needle-guide 2. This plane may be also arranged tobe secant to the position of the elongated hole for guiding the needle3, and in this case, a portion of the groove 702 must be obviously alsoprovided in the surface of the base part 102 against which the secondpart 202 rests.

Moreover, in this embodiment, the mutual position of the twoneedle-guide parts is maintained by complementary engagement meanstransverse to the needle axis, on the rear side of the needle-guide,from the end engagement between the two needle-guide parts to the frontend.

According to a possible variant, which will be explained more clearly inthe description of the next embodiment, the separation plane between thetwo needle-guide parts may also have a square wave profile, as relatedto the cross section of the needle-guide.

Here, for example, extensions may be provided not only for the front endof the second part 202 of the needle-guide 2, but also for the sidewalls of the groove 702, in this case forming ribs which project on bothsides of the groove, toward the surface resting on the base 102 of theneedle-guide 2. The base may have a groove of such a width and depth asto accommodate in a substantially accurate manner the two ribs extendingfrom the side walls of the groove 702, which form the bottom of thegroove in the base 102, and the wall for completing and/or closing theelongated needle guiding hole. The whole may be dimensioned in such amanner that the lumen and size of said elongated hole for guiding theneedle 3 has the necessary size to accommodate the needle safely andpossibly in an axially slidable manner. As stated above, other variantsare also possible, e.g. one of the two ribs extending from the sidewalls of the groove 702 may be integral with the second part 202 of theneedle-guide 2 while the other is integral with the base 102 of theneedle-guide 2, or longitudinally discontinuous ribs may be provided onboth parts 102, 202, alternating in such a manner as to be mutuallyengaged in a comb-like arrangement.

FIGS. 11 to 19 show an additional embodiment of a combination of a probe11 and a needle-guide 12 according to the invention.

Referring to this embodiment, the probe 11 is of the type ordinarily inuse for external imaging applications and has a handgrip part 111 and awidened head 211, which is curved on the front side and bulged in thedirection of the axis of curvature, and forms a transverse shoulder onthe rear side 311 for connection to the handgrip 111.

The needle-guide 12 is still composed of two parts, a base part 112 anda second part 212 which is removably securable to the base 112 and formsneedle guiding holes therewith.

The base 112 has means for securing it to the probe 1, which consist oftwo lateral front wings 312 which are shaped in such a manner 11 as toadhere to the bulged portion of the case of the probe 11 in the endtapered portion thereof and on the two opposite surfaces with referenceto the axis of curvature of the head of the probe 11. The base 112 hason its rear side a rear extension 312′ which extends behind the shoulder311 formed by the widened head of the probe 11, and the rear extension312′ has a threaded clamping bolt which is tightened against saidshoulder 311.

Also, other connection means may be provided, not shown in the Figures,like those described in the previous embodiment, such as combinations ofcentering ridges and recesses over the case of the probe 11 and the base112, as well as possible profiles of the case and of the wall of thebase 112 turned toward it to define a certain orientation angle for theneedles, to allow at least one of the needles 3 to be brought inside thescan area.

The needle-guide 12 is made in such a manner as to have three needleguiding holes and to be able to house three needles 3 at the same time.If the needles 3 were disposed all on the same plane, then theneedle-guide 12 might have substantially the same construction as thatof the needle-guide 2 of the previous embodiment.

However, in this embodiment the needles are in such a relativearrangement that their axes are coincident with the vertices of atriangle, particularly an isosceles or equilateral triangle. Therefore,the axis of one needle guiding hole is not on the same plane as theother two holes.

In order to ensure, nevertheless, that the needle guiding holes are atleast partly openable on one side, by simply separating the two parts112, 212 of the needle-guide, the separation surface has a cross sectionshaped like a rectangular curve.

The base 112 has a groove 612 in the middle position of the surface 512for supporting the second removable part 212 of the needle-guide. In thebottom wall of said groove 612 an additional parallel groove 712 isprovided, which has a proper size for the needle guiding hole, whereasthe second removable part 212 of the needle-guide 12 has a rib 812 in aposition coinciding with the groove 612, which engages in the groove 612when said two parts 112, 212 are mutually connected, and forms themissing closing side of the guiding hole with the edge turned toward theinner groove 712.

The other two guiding holes are formed by two grooves 912 formed in thetwo abutment surfaces of the second removable part 212 against thefacing surfaces of the base 112, which are disposed on the two sides ofthe rib 812. Said two grooves 912 have such a depth and such a widththat, like the groove 712, form the two additional guiding holes, withthe abutment surfaces 512 on the base part 112.

Obviously, the size of the rib 812 and of the groove 612 are such that,when said rib 812 abuts against the bottom of the groove 612, theabutment surfaces with the grooves 912 also abut against the surfaces512 of the base part.

In the end walls of the area of the rib 812, niches or recesses 912 maybe provided, for instance for gripping purposes.

As is apparent from the above, the inventive principle allows to providedifferent configurations of several substantially parallelneedle-guiding holes, having any different position.

In order that the second removable part 212 of the needle-guide 12 maybe held in position on the base 112, the latter has side walls 13 whichoverlap the side walls of the second part 212 of the needle-guide. Thetwo parts may be fastened in a substantially identical, through revertedmanner, with respect to the previous embodiment. One of the side wallsof the second part 212 of the needle-guide has a threaded hole intowhich a threaded pin 8, having a widened head 108 may be screwed,whereas, in a coincident position, the corresponding side wall 12 of thebase part 112 has a recess for engaging the pin which is open on theside in which said second part 212 of the needle-guide is introducedbetween the walls 13 of the base part 112 of the needle-guide.

Once again, in this example, the hole into which the pin is screwed maybe a through hole and the side wall 13 on the side opposite to the onethrough which the pin 8 is screwed may have a coincident hole in whichthe end of the threaded pin is engaged in the same manner as in theprevious embodiment when the two parts are clamped or almost clampedtogether.

It shall be noted that, when needed, the three-needle configuration ofthe needle-guide 12 may be extended without requiring any inventiveactivity to the endocavitary probe-specific embodiment, described withreference to FIGS. 1 to 10, the front head part of the needle-guidebeing easily changeable by anyone skilled in the art.

The inclination of the three needles, and their mutual position are suchthat one needle is situated closer to the probe and in such a positionas to be able to enter the scan field thereof. The other two needles arebeyond said scan field, but have a well defined and predeterminedposition. Particularly, the arrangement of the axes of the three needlesat the vertexes of a triangle allows to easily locate the other twoneedles when the first is imaged upon scanning and also allows toperform a local treatment over a wider area. It shall be also noted thatthe provision of several needle guiding holes allows the combined use ofa greater number of therapeutic and diagnostic tools, thereby allowingboth a combination of therapeutic and/or surgical actions and the use ofadditional control probes near the therapeutic or surgical action area,to improve monitoring of the operations, both visually, by ultrasoundimaging, and by detecting additional measurable parameters.

Moreover, the grooves which generate the guiding holes in combinationwith the facing abutment surfaces on the other part of the needle-guide12 may be provided, for the same hole, on the one or the other of thetwo parts of the needle-guide and may also have extensions of the sidewalls, as described in the previous embodiment, any combination orsubcombination of the characteristics described with reference to oneembodiment with one or more characteristics or with subcombinations orwith the complete combination of characteristics described withreference to the other embodiment as illustrated and described in thepresent disclosure being allowed.

The invention is not limited to the embodiments described andillustrated herein, but may be widely varied, especially as regardsconstruction, without departure from the guiding principle disclosedabove and claimed below. So, for example, while the needle-guides of theinvention are described and shown in combined applications withultrasound probes, they may be also used with other probes or othertherapeutic or diagnostic tools.

1. A needle-guide device for a medical probe comprising a base bodyhaving means for connection to the probe and an elongated guide hole forreceiving a needle, characterized in that said needle-guide device ismade of at least two removably connectable parts, which are shaped insuch a manner that each of them forms complementary and substantiallysymmetrical parts of the peripheral delimiting wall of said elongatedguide hole for a needle, which peripheral wall parts complete each otherwhen said complementary and substantially symmetrical parts of theneedle-guide device are connected, thereby forming and maintaining saidelongated guide hole for accurately guiding the needle with a 360 degreecovering delimiting wall over substantially the entire length of saidguide hole, said removably connectable parts being engaged in anon-separable and non-sliding condition by removable mutual mechanicallocking means, and said elongated guide hole having rectangular sectionsdimensioned to contact said needle at needle-guiding surfaces tangent tothe outer surface of said needle, thereby restricting transversemovement of said needle in said guide hole.
 2. A needle-guide device asclaimed in claim 1, characterized in that the two parts of theneedle-guide device have mutual abutment surfaces which are tangent orsecant to the elongated guide hole for guiding the needle, whereas saidelongated guide hole is obtained by a combination of grooves which areformed either integrally on one of the mutual abutment surfaces of oneof the two parts of the needle-guide device or partly on one and partlyon the other of the two abutment surfaces of both parts of theneedle-guide device.
 3. A needle-guide device as claimed in claim 2,characterized in that the two mutual abutment surfaces of the two partsof the needle-guide device have each a groove whose width corresponds tothe width of the needle and a partial depth relative to thecorresponding dimension of the needle, the two grooves being coincidentand completing mutually when the two parts of the needle-guide deviceare connected thereby forming the elongated guide hole for guiding theneedle.
 4. A needle-guide device as claimed in claim 1, characterized inthat the separation plane between the two parts of the needle-guidedevice is parallel to the axis of the elongated guide hole and secant orsubstantially tangent to the hole.
 5. A needle-guide device as claimedin claim 1, characterized in that said elongated guide hole has asection which corresponds to the outer section of the needle, with thewall of the elongated guide hole adhering to the whole needle surface.6. A needle-guide device as claimed in claim 1, characterized in thatsaid elongated guide hole has polygonal sections having such a size asto be able to inscribe therein the cylindrical or elliptical or ovalsection of the needle and generating needle-guiding surfaces tangent tothe outer surface of the needle.
 7. A needle-guide device as claimed inclaim 1, characterized in that the needle-guide device is composed of atleast two removable parts, at least one base part and at least onesecond part, which two parts are separated from each other by aseparation surface whose cross section is a broken rectangular curve,and forms a succession of alternate and parallel complementaryengageable ribs, there being provided, in the opposite mutual abutmentsurfaces of the ribs of one or both of the two parts of the needle-guidedevice grooves having such a size and shape as to form together saidelongated guide hole.
 8. A needle-guide device as claimed in claim 7,characterized in that the broken rectangular line-shaped separationsurface between said two parts of the needle-guide has constant orvariable widths to generate guiding holes aligned on one or more planesand with different relative positions.
 9. A needle-guide device asclaimed in claim 7, characterized in that the base part of theneedle-guide device has at least a longitudinal groove in the surfaceabutting against the second removable part of the needle-guide device,for engagement of longitudinally continuous or discontinuous extensionsof the side walls of a longitudinal groove formed in said secondremovable part of the needle-guide device, thereby forming the bottom ofthe longitudinal groove of the base, the missing completing wall of theelongated guide hole, whose additional delimiting walls are formed bythe bottom of the longitudinal groove in said second part of theneedle-guide device, the side walls of said groove and the extensions ofsaid side walls of the groove in said second part of the needle-guidedevice.
 10. A needle-guide device as claimed in claim 9, characterizedin that said second part of the needle-guide device has a singleextension of one of said two side walls of the longitudinal groove, asecond extension being provided on said base part as an extension of theopposite side wall of the longitudinal groove in the base part of theneedle-guide device, whereby each of the two parts of the needle-guidedevice forms two of the opposite walls of the elongated guide hole. 11.A needle-guide device as claimed in claim 9, characterized in that thearrangement of the extensions of the side walls of the grooves in thetwo parts of the needle-guide device is alternate and complementary overthe length of the two extensions in the longitudinal direction of thegrooves, either on one side and along the two opposite sides.
 12. Aneedle-guide device as claimed in claim 1, characterized in that theneedle-guide device may be divided in such a manner as to consist ofmore than two parts shaped in such a manner as to form complementaryparts of the peripheral delimiting wall of said elongated guide hole.13. A needle-guide device as claimed in claim 1, characterized in thatsaid base body has an abutment or support surface for the second part ofthe needle-guide device, which second part has in turn at least onelongitudinal groove whose size corresponds to the needle size, and formsthe side walls and a wall transverse thereto for delimiting theneedle-guiding hole, whereas its support surface on the base of theneedle-guide device forms the missing wall of the elongated guide hole,when the two parts of the needle-guide device are connected.
 14. Aneedle-guide device as claimed in claim 1, characterized in that it hasmeans for centering and partially interlocking the two parts of theneedle-guide device.
 15. A needle-guide device as claimed in claim 1,characterized in that the two parts of the needle-guide device haveremovable mutually locking means.
 16. A needle-guide device as claimedin claim 15, characterized in that the two parts of the needle-guidedevice have mutually clamping screw threaded means.
 17. A needle-guidedevice as claimed in claim 16, characterized in that the mutuallyclamping screw threaded means of the two parts of the needle-guidedevice have means for engaging said two parts of the needle-guide devicein an non-separable condition, and in a incompletely clamped condition.18. A combination of a needle-guide device having a base and anultrasound probe comprising a body and a scan head, characterized inthat the base of the needle-guide device is removably attachable to theprobe body in a stable and predetermined position, said base having atleast one shape mating extension which corresponds to a complementaryshape mating portion of the outer surface of the ultrasound probe bodyto form mutual interlocking engagement means, further characterized inthat it includes an external ultrasound probe having a bulged shape anda wider head as compared with the handgrip, wherein the probe head hasits greatest circumference in an intermediate position between the frontend and the portion connected to the handgrip, whereas the needle-guidedevice has a base having two preferably symmetrically coincidentextensions before the greatest circumference of the probe head, and anextension with a fastening screw which overlaps a rear side of thewidened head against which the fastening screw is tightened.
 19. Incombination: a needle-guide device for a medical probe comprising a basebody having means for connection to the probe and an elongated guidehole for receiving a needle, characterized in that said needle-guidedevice is made of at least two removably connectable parts, which areshaped in such a manner that each of them forms complementary andsubstantially symmetrical parts of the peripheral delimiting wall ofsaid elongated guide hole for a needle, which peripheral wall partscomplete each other when said complementary and substantiallysymmetrical parts of the needle-guide device are connected therebyforming and maintaining said elongated guide hole for accurately guidingthe needle with a 360 degree covering delimiting wall over substantiallythe entire length of said ride hole, said removably connectable partsbeing engaged in a non-separable and non-sliding condition by removablemutual mechanical locking means, and said elongated guide hole havingrectangular sections dimensioned to contact said needle atneedle-guiding surfaces tangent to the outer surface of said needle,thereby restricting transverse movement of said needle in said guidehole; and an ultrasound probe, said ultrasound probe comprising a bodyand a scan head, the said body and scan head having a cylindrical orslightly frustoconical shape with a rounded end of the scan head, saidneedle-guide device being removably attachable to the probe body in astable and predetermined position in which the axis of the needle, andof the needle-guide device and the axis of the probe are contained in acommon plane, said base body having a clamping collar at its rear endfor clamping the needle-guide device to the body of the probe in aregion of the said body of the probe at its rear end and the said basebody having at its front head an extension toward the probe engaging acentering recess in the probe head, the depths of the recess and theprofile of the probe head and of the front head of the needle-guidedevice being such that in the assembled position the steeper front sideof the said front head of the needle-guide device is joined to the outersurface of the probe head substantially without forming any steptherewith and being connected therewith in a substantially harmonicmanner.